Methicillin Resistant Staphylococcus aureus
About MRSA Methicillin resistant Staphylococcus aureus strains are responsible for severe infections in immunocompromised patients, the geriatric population, and in neonates. This bacterium in general is a well known etiological agent of many hospital-acquired infections. Through the process of natural selection and selective pressure, various strains of S. aureus have become resistant to beta lactam antibiotics, including the penicillins and cephalosporins. A recent increase in the number of MRSA strains leads to difficulties in treatment, and an increase in mortality and morbidity in those infected. MRSA manifests itself clinically in forms such as skin and soft tissue infections, bacteremia, endocarditis, pneumonia, and toxic shock syndrome. The recent increase in these persistent antibiotic resistant infections can be attributed to inappropriate use of broad spectrum antibiotics in clinical settings, as well as invasive procedures and an increase in the number of surgical interventions being preformed. The colonization causing nosocomial infections are endogenous infections caused by microorganisms inhabiting the patient's pharynx, nasal cavity, and skin. Transmission vectors such as other patients, medical personnel, and medical devices also facilitate the spread of infection. As a result, a study was preformed to analyze specific genes involved in antibiotic resistant Staph. In this study, 26 different specimens containing the bacteria were collected form the neonatal intensive care unit in the Uludag University Hospital. Genetic analysis of MRSA Once cultured from the NICU, the bacterial genome was amplified using PCR techniques. After PCR was preformed, the DNA was then run on a gel using pulsed field gel electrophoresis (PFGE). A combination of these two methods showed that all S. aureus grown in all 26 specimens were identified as MRSA. Nine out of the ten were evaluated as infectious agents, and these patients were treated using glycopeptides. In this study, PFGE was used to fingerprint the DNA of MRSA. The DNA was digested by SmaI restriction enzymes and divided into 10 to 20 pieces differing from 10 to 800 kilobase pairs. All of the patients survived the infection, and it was found that the mecA gene was present in all isolates containing the antibiotic resistance. Although differences and similarities were seen within the genomes of the various bacterial stains, a unique similarity was the presence of mecA. Further Observations Due to the fact that all the strains isolated were different, this showed many differences in the bacterial genomes. However the consistent presence of the mecA gene between different strains shows that this could be the genetic cause for resistance. The source of the outbreak of the isolated samples was though to be the first isolate of patient one. Infection control precautions were no implemented until the time passed during isolation, identification, and reporting of the strains had been done. This resulted in the spread of MRSA to other patients in the NICU, which further encouraged the infectious outbreak. As a result of this study, it is evident that to manage and terminate future outbreaks, tests to determine the genetic relation between outbreak strains are crucial and completely necessary. Identifying genetic causes for resistance by preforming genetic analysis on outbreak strains, will help to improve and prevent the spread of various strains in the future. References 1. [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4161569/ Agca, Harun. "Investigation of Methicillin Resistant Staphylococcus Aureus in Neonatal Intensive Care Unit." NCBI. PubMed, 14 Aug. 2014. Web. 26 Oct. 2014.] 2. [[wikipedia:Methicillin-resistant_Staphylococcus_aureus|"Methicillin-resistant Staphylococcus Aureus." Wikipedia. Wikimedia Foundation, 24 Oct. 2014. Web. 26 Oct. 2014.]] 3[http://blogs.plos.org/publichealth/2013/03/05/drug-resistance-in-mrsa-is-finely-tuned/ . "Drug Resistance in MRSA Is Finely-tuned." Public Health. N.p., 5 Mar. 2013. Web. 26 Oct. 2014.]